Hearing aids are wearable hearing devices, which serve to assist the hearing impaired. To satisfy the numerous individual requirements, different models of hearing aids are available, such as behind-the-ear hearing aids (BTE) and in-the-ear hearing aids (ITE) as well as concha hearing aids and completely-in-the-canal hearing aids (CIC) for example. The hearing aids listed by way of example are worn on the outer ear or in the auditory canal. Also available on the market are bone conduction hearing aids and implantable or vibrotactile hearing aids. Here the damaged hearing is stimulated either mechanically or electrically.
The essential components of hearing aids are in principle an input converter, an amplifier and an output converter. The input converter is generally a sound receiver, e.g. a microphone, and/or an electromagnetic receiver, e.g. an induction coil. The output converter is generally in the form of an electro-acoustic converter, e.g. a miniature loudspeaker, or an electromechanical converter, e.g. a bone conduction receiver. The amplifier is generally integrated in a signal processing unit. This basic structure is shown in FIG. 1 using the example of a behind-the-ear hearing aid. One or more microphones 2 for picking up the sound from the surroundings are built into a hearing aid housing 1 to be worn behind the ear. A signal processing unit 3, which is likewise integrated in the hearing aid housing 1, processes the microphone signals and amplifies them. The output signal of the signal processing unit 3 is transmitted to a loudspeaker or receiver 4, which outputs an acoustic signal. In some instances the sound is transmitted by way of a sound tube, which is fixed in the auditory canal with an otoplastic, to the eardrum of the aid wearer. Power is supplied to the hearing aid and in particular to the signal processing unit 3 by way of a battery 5, which is likewise integrated in the hearing aid housing 1.
BTE hearing aids are frequently provided with an external receiver unit. This external receiver unit is inserted into the ear canal and receives its electrical signals from a hearing aid main unit worn behind the auricle.
The external receiver unit generally consists of an ear mold, in which a loudspeaker or receiver is secured. The receiver is snap-fitted in the ear mold for example. To this end the receiver has a receiver connector, which forms a snap-fit connection with the ear mold. Both components of the snap-fit connection are typically made of polyamide.